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| United States Patent |
5,564,249
|
|
Borys
, et al.
|
October 15, 1996
|
Automotive trim piece
Abstract
A molding for installation on a vehicle which includes a decorative
injection-molded polymeric skin secured to an outwardly facing portion of
an elongate core and method of manufacture thereof. The skin extends along
the length of the molding and includes a cap unitarily formed therewith at
each end of the molding. Each cap is shaped to conceal the core when the
molding is installed on the vehicle. The skin of the molding may be
secured to the core by a heat activable adhesive. Alternatively, the
molding includes an extruded first polymeric layer compatible with the
polymeric skin between a first area of the outwardly facing portion of the
core and the skin, the skin being directly bonded to the extruded
polymeric layer and the extruded polymeric layer being adhesively bonded
to the core.
| Inventors:
|
Borys; Tadeusz (148 Tree Grove Circle, Aurora, Ontario, CA);
Zohar; Avi (79 Mountbatten Road, Thornhill, Ontario, CA);
Deleon; Albert (14 Lafferty Street, Etobicoke, Ontario, CA)
|
| Appl. No.:
|
021169 |
| Filed:
|
February 22, 1993 |
| Current U.S. Class: |
52/716.5; 49/490.1; 52/716.8; 52/717.01; 52/717.04; 52/717.05; 296/146.2; 428/31; 428/122 |
| Intern'l Class: |
B60R 013/04 |
| Field of Search: |
49/482.1,490.1,492.1
52/717.01,717.04,717.05,716.5,716.8
293/128
296/146.2,146.3
428/31,122
|
References Cited
U.S. Patent Documents
| 1476509 | Dec., 1923 | Hart.
| |
| 2724877 | Nov., 1955 | Ramsay | 49/490.
|
| 2910033 | Oct., 1959 | Weisburg.
| |
| 3122804 | Mar., 1964 | Stawinski.
| |
| 3188730 | Jun., 1965 | Meyer.
| |
| 3359030 | Dec., 1967 | Newman.
| |
| 3388523 | Jun., 1968 | Evans.
| |
| 3506294 | Apr., 1970 | Newman.
| |
| 3606432 | Sep., 1971 | Honatzis.
| |
| 3606433 | Sep., 1971 | Kunevicius.
| |
| 3681887 | Aug., 1972 | Loew.
| |
| 3687502 | Aug., 1972 | Loew.
| |
| 3752521 | Aug., 1973 | Lafebre.
| |
| 3770545 | Nov., 1973 | Jackson.
| |
| 3777438 | Dec., 1973 | Brown.
| |
| 3780152 | Dec., 1973 | Friesner.
| |
| 3788008 | Jan., 1974 | Yackiw et al.
| |
| 3817016 | Jun., 1974 | Barenyi.
| |
| 3856194 | Dec., 1974 | Helm.
| |
| 3894763 | Jun., 1975 | Barenyi.
| |
| 3934385 | Jan., 1976 | Paulus et al. | 52/716.
|
| 4042741 | Aug., 1977 | Bright.
| |
| 4052497 | Oct., 1977 | Monnet.
| |
| 4066285 | Jan., 1978 | Hall et al.
| |
| 4083592 | Apr., 1978 | Rubin et al.
| |
| 4100243 | Jun., 1978 | Wissinger et al.
| |
| 4183778 | Jan., 1980 | Mesnel.
| |
| 4220365 | Sep., 1980 | Foster et al.
| |
| 4220681 | Sep., 1980 | Narita.
| |
| 4235466 | Nov., 1980 | Mandrik.
| |
| 4246303 | Jan., 1981 | Townsend.
| |
| 4298640 | Nov., 1981 | Katoh | 428/31.
|
| 4318764 | Mar., 1982 | VanManen.
| |
| 4352772 | Oct., 1982 | Bezner.
| |
| 4358482 | Nov., 1982 | Jubelt.
| |
| 4381273 | Apr., 1983 | Azzola.
| |
| 4411941 | Oct., 1983 | Azzola.
| |
| 4419844 | Dec., 1983 | Kreisfeld.
| |
| 4478897 | Oct., 1984 | Akashi et al.
| |
| 4513044 | Apr., 1985 | Shigeki et al.
| |
| 4535024 | Aug., 1985 | Parker | 428/31.
|
| 4603899 | Aug., 1986 | Iwasa | 428/122.
|
| 4617209 | Oct., 1986 | Ives | 293/128.
|
| 4619847 | Oct., 1986 | Jackson.
| |
| 4676856 | Jun., 1987 | Shigeki et al.
| |
| 4708351 | Nov., 1987 | Midooka et al.
| |
| 4709525 | Dec., 1987 | Adell.
| |
| 4778550 | Oct., 1988 | Barton et al.
| |
| 4783931 | Nov., 1988 | Kirkwood.
| |
| 4800699 | Jan., 1989 | Lang.
| |
| 4861530 | Aug., 1989 | Zaccaria.
| |
| 4949507 | Aug., 1990 | Vaughan | 49/482.
|
| 4965103 | Oct., 1990 | Roberts et al.
| |
| 5085902 | Feb., 1992 | Yada et al.
| |
| 5143772 | Sep., 1992 | Iwasa | 428/122.
|
| 5149478 | Sep., 1992 | Malm.
| |
| 5151307 | Sep., 1992 | Jackson.
| |
| 5182141 | Jan., 1993 | Borys et al.
| |
| 5194312 | May., 1993 | Verig | 52/716.
|
| 5207027 | May., 1993 | Larsen | 49/482.
|
| 5221564 | Jun., 1993 | Keys | 428/122.
|
| 5240751 | Aug., 1993 | Cakmakci | 428/31.
|
| 5277950 | Jan., 1994 | Zoller | 428/31.
|
| 5350608 | Sep., 1994 | Zoller | 428/31.
|
| Foreign Patent Documents |
| 0046002 | Feb., 1982 | EP.
| |
| 482999 | Apr., 1992 | EP | 296/146.
|
Primary Examiner: Friedman; Carl D.
Assistant Examiner: Wilkens; Kevin D.
Attorney, Agent or Firm: Hunt; John C.
Claims
What is claimed is:
1. A molding for installation on a vehicle, comprising:
an elongate core having an outwardly facing portion and an inwardly facing
portion when installed on the vehicle;
a decorative injection-molded thermoplastic polymeric skin secured to the
outwardly facing portion of the core along the length of the molding, the
skin having a cap unitarily formed therewith at each end of the molding,
each cap shaped to conceal the core when the molding is installed on the
vehicle;
an extruded first polymeric layer compatible with the polymeric skin
adhesively bonded to a first area of the outwardly facing portion of the
core, the skin being directly bonded to the extruded polymeric layer; and
a second polymeric layer secured directly to a second area of the core, the
second polymeric layer selected from the group of ethylene propylene diene
monomer and thermoplastic elastomeric materials.
2. The molding of claim 1 wherein the extruded polymeric layer and the
polymeric skin are each of polyvinyl chloride.
3. The molding of claim 2 wherein the core is tapered from one of the ends
thereof to the other.
4. The molding of claim 2 wherein the core is of constant cross-section
along its length.
5. The molding of claim 2 wherein the core has a "U"-shaped cross-section
having first and second legs for installation along an upper portion of a
door panel of the vehicle.
6. The molding of claim 1 wherein the extruded polymeric layer and the
polymeric skin are together selected from the group of: thermoplastics
including polypropylene; modified polypropylene; and thermoplastic
elastomeric materials.
7. The molding of claim 1 wherein the injection-molded skin and end caps
are seamless.
8. The molding of claim 1 wherein the core is of roll-formed metal.
9. The molding of claim 1 wherein a first visible region of the skin
presents a relatively high gloss appearance and a second visible region of
the skin presents a relatively low gloss appearance.
10. A molding for installation on a vehicle, comprising:
an elongate core of "U"-shaped cross-section and having first and second
legs for installation along an upper portion of a door panel of the
vehicle and an outwardly facing portion of the core and an inwardly facing
portion of the core when installed on the vehicle, the first leg including
the outwardly facing portion of the core and the second leg having an
extruded layer of a first polymeric layer chemically adhered thereto;
a decorative injection-molded thermoplastic polymeric skin of polyvinyl
chloride secured to the outwardly facing portion of the core along the
length of the molding, the skin having a cap unitarily formed therewith at
each end of the molding, each cap shaped to conceal the core when the
molding is installed on the vehicle; and
an extruded second polymeric layer of polyvinyl chloride compatible with
the polymeric skin adhesively bonded to a first area of the outwardly
facing portion of the core, the skin being directly bonded to the extruded
polymeric layer.
11. A molding for installation on a vehicle, comprising:
an elongate core of "U"-shaped cross-section and having first and second
legs for installation along an upper portion of a door panel of the
vehicle and an outwardly facing portion of the core and an inwardly facing
portion of the core when installed on the vehicle, the first leg including
the outwardly facing portion of the core and the second leg having an
extruded layer of a thermosetting polymer chemically bonded thereto;
a decorative injection-molded thermoplastic polymeric skin of polyvinyl
chloride secured to the outwardly facing portion of the core along the
length of the molding, the skin having a cap unitarily formed therewith at
each end of the molding, each cap shaped to conceal the core when the
molding is installed on the vehicle; and
an extruded first polymeric layer of polyvinyl chloride compatible with the
polymeric skin adhesively bonded to a first area of the outwardly facing
portion of the core, the skin being directly bonded to the extruded
polymeric layer.
12. The molding of claim 11 wherein the thermosetting polymer comprises
ethylene propylene diene monomer and the molding further comprises a
flocking layer bonded to the thermosetting polymer for abutment of a
window of the vehicle when installed thereon.
13. The molding of claim 11 wherein the core is of roll-formed metal and
the first leg has an outwardly convex cross-section.
Description
FIELD OF THE INVENTION
This invention is in the field of moldings for installation on vehicles. In
particular, this invention relates to a belt molding having a decorative
plastic portion and unitarily formed plastic caps at the ends of the
molding.
BACKGROUND TO THE INVENTION
There are many known molding products and methods of manufacture of such
products.
U.S. Pat. No. 3,780,152 (Friesner) which issued Dec. 18, 1973, discloses a
method and apparatus for producing a trim strip assembly. The trim strip
has an extruded thermoplastic base member having a strip member with a
metal-like appearance superimposed thereon and a transparent extruded
plastic top coating.
U.S. Pat. No. 4,100,243 (Wissinger et al.) which issued Jul. 11, 1978,
discloses a process for sizing an extruded thermoplastic structure formed
by coextrusion of a core profile of one thermoplastic material and a cover
layer of another thermoplastic material provided over a portion of the
periphery of the core profile.
U.S. Pat. No. 4,183,778 (Mesnel) which issued Jan. 15, 1980, discloses a
method for joining two extruded strips at a miter joint, where each strip
includes a thermoplastic gripper portion glued to a thermosetting
elastomer portion. The method involves the injection of a polyurethane
thermoplastic resin into the joint between the thermoplastic portions and
contemporaneous curing of the elastomeric portions.
U.S. Pat. No. 4,220,681 (Narita) which issued Sep. 2, 1980, discloses a
trim piece for automobiles. A thin metal layer is integrally laminated on
a plastic substrate and the metal layer is partially or wholly coated with
a soft PVC resin.
U.S. Pat. No. 4,352,772 (Bezner) which issued Oct. 5, 1982, discloses a
method and apparatus for injection-molding a plastic manifold onto tubular
elements.
U.S. Pat. No. 4,478,897 (Akashi et al.) which issued Oct. 23, 1984,
discloses a compound molding including a metal portion having polyvinyl
chloride or the like extruded onto it. There is an intermediate extruded
acrylonitrile butadiene styrene layer or the like between the metal
portion and the polyvinyl chloride portion.
U.S. Pat. No. 4,861,530 (Zaccaria) which issued Aug. 29, 1989, discloses a
method for sizing a weather strip as it is manufactured by omitting
portions of extruded materials which then act as reference points for a
cutting operation. A weather strip having a metal core surrounded by
extruded elastomeric material is shown.
U.S. Pat. No. 4,965,103 (Roberts et al.) which issued Oct. 23, 1990,
discloses a method and apparatus for extruding a molding strip having an
outer polyurethane layer bonded to a central PVC layer is described. A
reinforcing strip is embedded in the PVC portion.
U.S. Pat. No. 5,123,988 (Iwasa) which issued Jun. 23, 1992, discloses a
process for obtaining a cloth finish on an extruded rubber article.
U.S. Pat. No. 5,151,307 (Jackson) which issued Sep. 29, 1992 describes a
belt molding having "U"-shaped support member with a thermoplastic
elastomer material such as Santoprene 3101-64 extruded onto a first
portion and a thermoplastic material such as polyvinyl chloride extruded
onto a second portion.
U.S. Pat. No. 5,182,141 (Borys et al.) which issued Jan. 26, 1993,
describes an extruded trim piece having a metal substrate with a
terpolymer of ethylene propylene diene monomer (EPDM) coating bonded to
one area of the metal substrate and a polyvinyl chloride (PVC) coating
bonded to another area of the metal substrate.
A number of other patent documents disclose vehicle moldings:
______________________________________
Country & No.
Name Date
______________________________________
US 1,476,509 Hart December 4, 1923
US 2,910,033 Weisburg October 27, 1959
US 3,122,804 Stawinski March 3, 1964
US 3,188,730 Meyer June 15, 1965
US 3,606,433 Kunevicius Septemver 20, 1971
US 3,681,887 Loew August 8, 1972
US 3,687,502 Loew August 29, 1972
US 3,770,545 Jackson November 6, 1973
US 3,856,194 Helm December 24, 1974
US 4,246,303 Townsend January 20, 1981
US 4,800,699 Lang January 31, 1989
______________________________________
The foregoing documents thus describe a variety of molding products and
methods and apparatuses for product manufacture, but do not address
problems associated with providing the products with end members.
Automotive belt moldings are often required to be provided with end
members. End members are aesthetically and functionally desirable.
Moldings, at least as related to the present invention, have an elongate
core longitudinal ends of which are desired not to be exposed once the
molding is installed on a vehicle.
A belt molding is often hollow, having a central core with an interior
cross-sectional profile that does not match the exterior profile of the
portion of the vehicle to which it is attached. While a lower lengthwise
edge of such a molding mounted on a car door abuts the door, there is a
gap between the underside of the molding and the vehicle portion concealed
by the molding. End portions are thus desirable to bridge the gap between
the molding and vehicle part to which the molding is attached. This is
aesthetically desirable and also provides a sealing function to preclude
ingress of water. Further, end portions should be shaped to abut the
vehicle so as to prevent snagging of clothing, etc. by the molding. A
number of approaches has thus been taken to the provision of suitable end
portions as part of vehicle moldings.
U.S. Pat. No. 4,358,482 (Jubelt) which issued Nov. 9, 1982, discloses a
method for end finishing an elongated composite trim strip. The show
surface of a strip is coated with a mask material and the strip is cut so
that the mask material covers the show surface adjacent the cut end. The
end is painted and the mask material cut away.
U.S. Pat. No. 4,619,847 (Jackson) which issued Oct. 28, 1986, discloses a
trim strip having an injection molded finishing portion and a method for
manufacture thereof. An elongate extruded trim strip has ends modified by
cutters and each end is loaded into an injection molding die.
Thermoplastic material is injection molded onto each modified end.
According to this approach, a molding having a seam at each end, at the
interface of the strip and injection molded portion, is obtained. Further,
it is difficult to match the finish of the plastic trim strip, if it is
extruded, and the plastic of the injection-molded portion.
U.S. Pat. No. 5,085,902 (Yada et al.) which issued Feb. 4, 1992, provides a
possible solution to the problem of unsightly seams. In one disclosed
embodiment a metal core has a film laminated onto it. The resultant
product is roll-formed to the desired profile and longitudinal PVC edges
are extruded onto the core. The material is cut into strips and each end
of the strip has portions cut away to form notches. A portion of each end
is folded into place and PVC end portions are injection molded onto each
end. This approach is relatively complicated in that it requires cutting
and bending into place portions of each end of the strip. Further, it does
not fully address the problem of seams. There is still a seam between
extruded and injection molded portions and between laminate portion and
extruded portions. Presumably there is also a joint formed in corner areas
at each corner where the bent portion of the extruded strip meets the
remaining extruded portion.
U.S. Pat. No. 4,318,764 (VanManen) which issued Mar. 9, 1982, discloses a
method of extrusion and injection molding of a trimmed product. This
document describes a trim piece having an extruded trim strip onto which
is formed an injection molded part. The extruded trim strip includes a
decorative trim strip pressed onto an extruded (transparent) base. The
strip is bent and placed in a mold and a support shell is injected molded
onto its reverse face. The strip is flexible and is bent to match the
shape of the end portions of the extruded support. The strip thus provides
a decorative portion to an injection molded support.
Other approaches to furnishing moldings with end pieces are described in
the following documents:
______________________________________
Country & No.
Name Date
______________________________________
US 3,359,030 Newman December 19, 1967
US 3,388,523 Evans June 18, 1968
US 3,506,294 Newman April 14, 1970
US 3,606,432 Honatzis September 20, 1971
US 3,752,521 Lafebre August 14, 1973
US 3,777,438 Brown December 11, 1973
US 3,817,016 Barenyi June 18, 1974
US 3,894,763 Barenyi July 15, 1975
US 4,066,285 Hall et al. January 3, 1978
US 4,220,365 Foster et al.
September 2, 1980
US 4,235,466 Mandrik November 25, 1980
US 4,709,525 Adell December 1, 1987
______________________________________
SUMMARY OF THE INVENTION
The present invention provides a molding for installation on a vehicle
which includes a decorative injection-molded polymeric skin secured to an
outwardly facing portion of an elongate core. The skin extends along the
length of the molding and includes a cap unitarily formed therewith at
each end of the molding. Each cap is shaped to conceal the core when the
molding is installed on the vehicle.
The skin of the molding may be secured to the core by a heat activable
adhesive.
Alternatively, as described further below in connection with a preferred
embodiment, a molding of the present invention includes an extruded first
polymeric layer compatible with the polymeric skin between a first area of
the outwardly facing portion of the core and the skin, the skin being
directly bonded to the extruded polymeric layer. It is generally
preferable that such an extruded polymeric layer be adhesively bonded to
the core.
In illustrated embodiments, the extruded polymeric layer and the polymeric
skin are each of polyvinyl chloride, but the extruded polymeric layer and
the polymeric skin may together be selected from the group of:
thermoplastics including polypropylene; modified polypropylene; and
thermoplastic elastomeric materials.
The illustrated embodiments of the molding further comprise a second
polymeric layer secured directly to a second area of the core, which
second polymeric layer may be selected from the group of: ethylene
propylene diene monomer and thermoplastic elastomeric materials.
The molding may be tapered from one of its ends to the other or it may be
of constant cross-section along its length.
In particular embodiments, the core of the molding of the present invention
has a "U"-shaped cross-section so as to have first and second legs for
installation along an upper portion of a door panel of the vehicle. The
first leg may include the outwardly facing portion of the core and/or the
second leg may have the extruded second polymeric layer chemically adhered
thereto.
Most preferably, the injection-molded skin and end caps of the molding are
seamless.
In another aspect the present invention includes a method of making a belt
molding for installation on a vehicle. The method includes steps of
forming an elongate core to a predetermined configuration and cutting the
core to a predetermined length. Another step includes securing a
decorative polymeric skin along the length of the core including injection
molding the skin and a cap therefor at each end of the molding onto the
core unitarily, that is, in a single molding step.
The method may further include the step of extruding a layer of polymeric
material compatible with the polymeric skin onto a first area of the core
prior to the cutting step and the securing step may thus include injection
molding the skin directly onto the polymeric layer. Such a method may also
include the step of applying an adhesive to the first area of the core for
bonding the polymeric material to the core prior to the extruding step.
Methods according to the present invention may also include the step of
securing a polymer to a second area of the core prior to the cutting step.
In a particular embodiment, the present invention includes a method of
manufacturing a belt molding for installation on a vehicle in which the
method includes the steps of forming an elongate metal core to a
predetermined cross-section followed by extruding a thermosetting layer
along the length of the core and securing the layer to a first area of the
core. The method includes subsequently curing the thermosetting layer and
extruding a thermoplastic layer along the length of the core and securing
the thermoplastic layer to a second area of the core. This particular
method also includes securing flock along an area of the thermosetting
layer to present a low friction surface and subsequently cutting the core
to obtain a piece of suitable length and trimming away selected portions
of the piece to match the vehicle on which the molding is to be installed.
The method also includes injection molding a skin along the length of the
piece including a unitarily molded cap at each of its ends to conceal the
core when the molding is installed on the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 shows a first preferred embodiment belt molding installed on a
driver's side door of an automobile door;
FIG. 2 is an isometric view of a portion of the FIG. 1 molding, layered
portions being removed for illustrative purposes;
FIG. 3 shows a cross-sectional view of the FIG. 1 embodiment taken along
3--3 of FIG. 1; and
FIG. 4 is an isometric view of a second preferred embodiment untapered
molding.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Turning to the drawings, FIG. 1 shows an upper part of car door panel 10
having first embodiment belt molding 12 installed along the top of the
panel to abut window glass 14.
Belt molding 12 includes roll-formed aluminum strip 16 having a generally
"U"-shaped cross-section, which strip provides a relatively rigid core for
plastic portions of the molding. Extending from one end to the other of
the molding is injection-molded thermoplastic skin 18. Formed unitarily
with the skin are end caps 20. The end caps and skin are injection molded
at the same time in the same mold from the same material and in this way
are unitarily molded with each other. Further, the skin and caps of the
preferred embodiment are molded so as to be seamless, there being no seams
between the end caps and central portion of the strip visible once the
molding is installed on a vehicle.
The preferred embodiments described herein each include an extruded
polyvinyl chloride layer (PVC) 22 adhesively bonded to a portion of the
outwardly convex surface of outer leg 24 of installed strip 16. Injection
molded skin 18, being "compatible" with the underlying extruded portion
bonds directly to the extruded PVC layer without the need for adhesive
during the injection molding process. The inner leg 26 of the strip has
extruded onto it ethylene propylene diene monomer (EPDM) layer 28 having
flocking 30 which abuts the window glass. As best seen in FIG. 1, first
embodiment molding 12 is tapered, being of narrower cross-section at
forward end 32 than at rearward end 34. Second embodiment molding 36 is
similar to the first embodiment molding, but it is not tapered along its
length. The metal core of molding 36 is of constant cross-section along
its length from one end to the other.
Skin 18 and end caps 20 may alternatively be of modified polypropylene, a
blend of EPDM and polypropylene. It may also be desirable for the extruded
thermoplastic portion to be extruded onto a portion of the extruded EPDM
portion in addition to the metal core. Further, the injection-molded
thermoplastic portion may also be molded onto an EPDM portion as well as
to the metal or extruded thermoplastic portion as desired.
In a preferred process of manufacture according to this invention, an
aluminum substrate is cleaned, in preparation for application of the
adhesive to be used to bond an EPDM layer thereto as follows. After
rollforming, the formed aluminum strip is passed through an enclosed
cleaning tank where it is sprayed with warm alkaline solution. Typically,
the solution has a pH of about 10 to 12 and a temperature of about
60.degree. C., the conditions being sufficient to condition the metal for
adhesion of later applied adhesives and coatings. The strip is next passed
through a second rinse tank wherein it is sprayed with water in order to
remove the alkaline cleaning solution. The metal is then dried with a hot
air blast at about 90.degree. C. to 100.degree. C.
To a first area of the cleaned substrate was applied an EPDM primer
suitable for bonding EPDM to aluminum, "Chemlok 205" (trademark), a metal
primer including a combination of phenolics and chlorinated rubber
available from Lord Corporation. This was heated to give a surface
temperature of about 120.degree. C., the primer thereby being ready for
application of adhesive.
To the primed area was applied an EPDM adhesive suitable for bonding EPDM
to the primer, "Chemlok 250" (trademark), a heat-activable polyisocyanate
based adhesive also available from the Lord Corporation. This was heated
to give a surface temperature of about 120.degree. C., the adhesive
thereby being activated and ready for application of EPDM.
EPDM, available as Thona E3402D was then extruded in molten form onto the
metal substrate so as to apply the EPDM to the area of the substrate
covered by the adhesive.
To a second area of the substrate was applied a PVC adhesive known as
A1617B, a pigmented, modified acrylic adhesive available from B. F.
Goodrich, for bonding PVC to aluminum. This adhesive has the properties of
bonding PVC to the aluminum substrate and being heat activated under
conditions, as described below, suitable for curing the EPDM previously
applied to the substrate. An alternative adhesive is Sternson Adhesives
PR1029 which is also a heat-activable adhesive, although the activation
temperature is a few degrees higher.
The piece was then passed through an oven at 210.degree. C. to provide a
residence time of about 6 minutes wherein the EPDM was cured and the PVC
adhesive was activated.
Upon exit from the oven, PVC was extruded in molten form onto the substrate
so as to apply the PVC to the area of the substrate to which the PVC
adhesive was applied.
Flock adhesive known as "Flocklok 852" (trademark) with catalyst "Chemglaze
9988" (trademark) was applied to the desired region of the EPDM as known
to those skilled in the art, and the flock adhesive cured at about
190.degree. C., this taking about four minutes. Flock, a material which
presents a low friction surface to a glass window which it abuts, is then
applied.
The aluminum core with extruded layers secured thereto is then cut to
length. For first embodiment molding 12, the core is then crimped to
obtain the desired degree of taper. Metal and polymeric portions are then
trimmed away as can be seen in FIG. 1 to obtain trimmed portions 38, 40 to
match the portion of the vehicle to which the molding is to be attached.
The polyvinyl chloride skin is then injection-molded onto extruded PVC
layer 22.
The EPDM must be cured before extrusion of PVC onto the substrate since the
conditions necessary for curing the EPDM are too harsh for the PVC and
would damage the PVC, as for example, by causing the PVC to melt slightly
and lose its intended final shape.
The starting metal substrate used in the preferred process illustrated is
an aluminum strip or ribbon. Such a substrate of stainless steel or of
galvanized steel or of zinc would work equally well in the illustrated
example, but cleaning should be preceded by roughening. It would also be
possible to similarly roughen the aluminum substrate used in the above
example, although a satisfactory product was produced without the
application of a roughener.
The above example of a method of producing a product made in accordance
with this invention is intended to be illustrative. It is known that
shorter evaporation and curing times for adhesives and EPDM may be
achieved at higher temperatures. A typical temperature for activating the
EPDM adhesive is between about 110.degree. C. and 140.degree. C. A typical
temperature for curing the EPDM is between about 200.degree. C. and
260.degree. C. A flock adhesive curing temperature between 150.degree. C.
and 220.degree. C. may be used. In situations such as the preferred
embodiment of this invention wherein flock adhesive is applied to EPDM
after the metal has been coated with PVC, this curing temperature should
be kept low enough so as not to melt the PVC or spoil its finish through
overheating. For example, a temperature above about 220.degree. C. with a
residence time of 2 minutes would be considered excessive.
The disclosed molding 12 thus includes skin 18 and end caps 20 unitarily
molded with each other and presenting no visible seams once the molding is
installed on a vehicle. Because the skin and caps are unitarily molded,
there is no difficulty in matching the gloss or the colors of the skin and
cap portions. It will further be appreciated that the finish obtainable
with injection-molded PVC is of a higher gloss than that obtainable with
extruded PVC. In instances in which the underlying extruded PVC layer is
to be covered by the injection-molded skin and end caps so as not to be
visible when installed on a vehicle, the underlying PVC layer can be of a
lower grade, since its appearance is not important in the finished
molding. Further, it is possible, while avoiding parting lines between the
injection-molded skin and end caps to have a portion of the underlying
extruded portion exposed such that the visible plastic portion of the
molding presents two colors or surfaces having two gloss levels. Further,
it is possible to carry out the injection molding in two steps to obtain a
molding with two colored surfaces visible or surfaces having different
gloss levels. In such case seams between the end caps and skin are still
avoided, there being a line necessary at the interface of the differently
colored or differently glossed surfaces. Alternatively, a skin having one
visible region 42 of a first given texture, say a relatively smooth shiny
surface presenting a relatively high gloss and another region 44
presenting a second texture, say of a rough or dull, that is, relatively
low gloss surface is obtainable. As known to persons skilled in the art,
the texture of the interior surface of the mold against which the skin is
formed may be obtained, such as by machining, so as to yield such effects
in the molded product, as desired.
In the disclosed embodiment, the PVC extruded skin is about 0.01 inches
thick, the PVC injection-molded portion is about 0.06 inches thick at its
center and the aluminum core is about 0.02 inches in thickness.
It will also be noted that there is no need for mechanical fastening of the
injection-molded end caps to the core when the end caps and skin extending
the along the length of the molding, as in the disclosed embodiments, are
unitarily formed with each other. Further no modification of the extruded
strip is required after it is cut to the desired length for
injection-molding of the skin and end caps thereonto, although crimping
may be preferred, as in the case of the first disclosed embodiment and
trimming is often necessary, as described.
Adhesives are often required to be used in fastening organic polymeric
materials to metal supports in order to meet "peel test" requirements of
the automotive industry. A further advantage of the approach taken for the
preferred embodiment stems from an extruded plastic layer intermediate the
metal support and injection-molded finishing layer. Each of the preferred
embodiments requires application of an adhesive in an in-line extrusion
process to a support core, followed directly by extrusion of a polymer
thereto to secure the polymer to the core. This intermediate product is
then further modified, including steps involving trimming of the core and
EPDM layers. The final plastic layer is then injection-molded onto the
part without the requirement of an additional adhesive. Because the
injection-molded portion and underlying extruded portion to which it is
applied are compatible, sufficient bonding strength is provided between
these two layers so as to avoid the requirement for application of
adhesive for fastening the injection-molded portion. The bond between the
two compatible layers is believed to result from a sufficient melting
together of the layers during the injection-molding step. In any case,
avoidance of a step involving adhesive application is particularly
advantageous here because application of the adhesive, for practical
purposes would have to be accomplished after the modification steps and
such application to a cut piece is inconvenient relative to the in-line
application of same during a more or less continuous extrusion process.
While it is appreciated that there are advantages, as described above, to
the presence of an extruded polymeric layer between the core and
injection-molded portion, it is possible to injection-mold directly onto a
metal core treated with a suitable adhesive, a skin and end caps unitarily
molded with each other. Preferably, a heat-activable adhesive that would
be sufficiently activated by the heat generated during the injection
molding process would be used, thus avoiding the requirement of a separate
heating step to activate the adhesive.
Substitutions of materials may thus be made in the preferred embodiments as
follows: a thermoplastic elastomer (TPE) could be extruded and
injection-molded in place of corresponding PVC portions; similarly,
polypropylene could be substituted for PVC; alternatively, polypropylene
could be substituted for PVC and the EPDM layer could be substituted for
by a TPE; all three portions could be a TPE; or PVC could be applied and
secured as described and a TPE substituted in place of the EPDM portion.
Other combinations are obtainable by persons skilled in the art.
It is to be understood that the disclosed examples of the invention are
illustrative and that the scope of the invention is defined by the
appended claims.
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